Pre-Bötzinger Complex: a Brainstem Region that May Generate Respiratory Rhythm in Mammals

TLDR

The precise location of breathing rhythm‑generating neurons in mammals was previously unknown. Microsection studies in neonatal rat brainstem identified the pre‑Bötzinger Complex as a ventral medullary region essential for respiratory rhythm; removal of this region abolishes oscillations, slices containing it reproduce whole‑brainstem activity, and pacemaker‑like neurons suggest the rhythm arises from conditional bursting pacemakers in this complex.

Abstract

The location of neurons generating the rhythm of breathing in mammals is unknown. By microsection of the neonatal rat brainstem in vitro, a limited region of the ventral medulla (the pre-Bötzinger Complex) that contains neurons essential for rhythmogenesis was identified. Rhythm generation was eliminated by removal of only this region. Medullary slices containing the pre-Bötzinger Complex generated respiratory-related oscillations similar to those generated by the whole brainstem in vitro, and neurons with voltage-dependent pacemaker-like properties were identified in this region. Thus, the respiratory rhythm in the mammalian neonatal nervous system may result from a population of conditional bursting pacemaker neurons in the pre-Bötzinger Complex.